/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sosee.cgfw.view;

import java.util.Collection;
import java.util.HashSet;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.View;


import com.sosee.cgfw.R;


import com.sosee.cgfw.cameraname.CameraManager;
import com.google.zxing.ResultPoint;


/**
 * This view is overlaid on top of  camera preview. It adds the viewfinder
 * rectangle and partial transparency outside it, as well as the laser scanner
 * animation and result points.
 *
 */
public final class ViewfinderView extends View {
  private static final String TAG = "log";
  /**
   * 刷新界面的时间
   */
  private static final long ANIMATION_DELAY = 10L;
  private static final int OPAQUE = 0xFF;

  /**
   * 四个绿色边角对应的长度
   */
  private int ScreenRate;

  /**
   * 四个绿色边角对应的宽度
   */
  private static final int CORNER_WIDTH = 10;
  /**
   * 扫描框中的中间线的宽度
   */
  private static final int MIDDLE_LINE_WIDTH = 6;

  /**
   * 扫描框中的中间线的与扫描框左右的间隙
   */
  private static final int MIDDLE_LINE_PADDING = 5;

  /**
   * 中间那条线每次刷新移动的距离
   */
  private static final int SPEEN_DISTANCE = 5;

  /**
   * 手机的屏幕密度
   */
  private static float density;
  /**
   * 字体大小
   */
  private static final int TEXT_SIZE = 16;
  /**
   * 字体距离扫描框下面的距离
   */
  private static final int TEXT_PADDING_TOP = 30;

  /**
   * 画笔对象的引用
   */
  private Paint paint;

  /**
   * 中间滑动线的最顶端位置
   */
  private int slideTop;

  /**
   * 中间滑动线的最底端位置
   */
  private int slideBottom;

  /**
   * 将扫描的二维码拍下来，这里没有这个功能，暂时不考虑
   */
  private Bitmap resultBitmap;
  private final int maskColor;
  private final int resultColor;

  private final int resultPointColor;
  private Collection<ResultPoint> possibleResultPoints;
  private Collection<ResultPoint> lastPossibleResultPoints;

  boolean isFirst;

  public ViewfinderView(Context context, AttributeSet attrs) {
    super(context, attrs);

    density = context.getResources().getDisplayMetrics().density;
    //将像素转换成dp
    ScreenRate = (int)(20 * density);

    paint = new Paint();
    Resources resources = getResources();
    maskColor = resources.getColor(R.color.viewfinder_mask);
    resultColor = resources.getColor(R.color.result_view);

    resultPointColor = resources.getColor(R.color.possible_result_points);
    possibleResultPoints = new HashSet<ResultPoint>(5);
  }

  @Override
  public void onDraw(Canvas canvas) {
    //中间的扫描框，你要修改扫描框的大小，去CameraManager里面修改
    Rect frame = CameraManager.get().getFramingRect();
    if (frame == null) {
      return;
    }

    //初始化中间线滑动的最上边和最下边
    if(!isFirst){
      isFirst = true;
      slideTop = frame.top;
      slideBottom = frame.bottom;
    }

    //获取屏幕的宽和高
    int width = canvas.getWidth();
    int height = canvas.getHeight();

    paint.setColor(resultBitmap != null ? resultColor : maskColor);

    //画出扫描框外面的阴影部分，共四个部分，扫描框的上面到屏幕上面，扫描框的下面到屏幕下面
    //扫描框的左边面到屏幕左边，扫描框的右边到屏幕右边
    canvas.drawRect(0, 0, width, frame.top, paint);
    canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
    canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1,
            paint);
    canvas.drawRect(0, frame.bottom + 1, width, height, paint);



    if (resultBitmap != null) {
      // Draw the opaque result bitmap over the scanning rectangle
      paint.setAlpha(OPAQUE);
      canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
    } else {

      //画扫描框边上的角，总共8个部分
      paint.setColor(Color.GREEN);
      canvas.drawRect(frame.left, frame.top, frame.left + ScreenRate,
              frame.top + CORNER_WIDTH, paint);
      canvas.drawRect(frame.left, frame.top, frame.left + CORNER_WIDTH, frame.top
              + ScreenRate, paint);
      canvas.drawRect(frame.right - ScreenRate, frame.top, frame.right,
              frame.top + CORNER_WIDTH, paint);
      canvas.drawRect(frame.right - CORNER_WIDTH, frame.top, frame.right, frame.top
              + ScreenRate, paint);
      canvas.drawRect(frame.left, frame.bottom - CORNER_WIDTH, frame.left
              + ScreenRate, frame.bottom, paint);
      canvas.drawRect(frame.left, frame.bottom - ScreenRate,
              frame.left + CORNER_WIDTH, frame.bottom, paint);
      canvas.drawRect(frame.right - ScreenRate, frame.bottom - CORNER_WIDTH,
              frame.right, frame.bottom, paint);
      canvas.drawRect(frame.right - CORNER_WIDTH, frame.bottom - ScreenRate,
              frame.right, frame.bottom, paint);


      //绘制中间的线,每次刷新界面，中间的线往下移动SPEEN_DISTANCE
      slideTop += SPEEN_DISTANCE;
      if(slideTop >= frame.bottom){
        slideTop = frame.top;
      }
      canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop + MIDDLE_LINE_WIDTH/2, paint);


      //画扫描框下面的字
      paint.setColor(Color.WHITE);
      paint.setTextSize(TEXT_SIZE * density);
      paint.setAlpha(0x40);
      paint.setTypeface(Typeface.create("System", Typeface.BOLD));
      canvas.drawText(getResources().getString(R.string.scan_text), frame.left, (float) (frame.bottom + (float)TEXT_PADDING_TOP *density), paint);



      Collection<ResultPoint> currentPossible = possibleResultPoints;
      Collection<ResultPoint> currentLast = lastPossibleResultPoints;
      if (currentPossible.isEmpty()) {
        lastPossibleResultPoints = null;
      } else {
        possibleResultPoints = new HashSet<ResultPoint>(5);
        lastPossibleResultPoints = currentPossible;
        paint.setAlpha(OPAQUE);
        paint.setColor(resultPointColor);
        for (ResultPoint point : currentPossible) {
          canvas.drawCircle(frame.left + point.getX(), frame.top
                  + point.getY(), 6.0f, paint);
        }
      }
      if (currentLast != null) {
        paint.setAlpha(OPAQUE / 2);
        paint.setColor(resultPointColor);
        for (ResultPoint point : currentLast) {
          canvas.drawCircle(frame.left + point.getX(), frame.top+ point.getY(), 3.0f, paint);
        }
      }


      //只刷新扫描框的内容，其他地方不刷新
      postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
              frame.right, frame.bottom);

    }
  }

  public void drawViewfinder() {
    resultBitmap = null;
    invalidate();
  }

  /**
   * Draw a bitmap with the result points highlighted instead of the live
   * scanning display.
   *
   * @param barcode
   *            An image of the decoded barcode.
   */
  public void drawResultBitmap(Bitmap barcode) {
    resultBitmap = barcode;
    invalidate();
  }

  public void addPossibleResultPoint(ResultPoint point) {
    possibleResultPoints.add(point);
  }

}
